Deputy Prime Minister Nick Clegg has defended the Prince of Wales' right to "express himself" in the wake of his reported controversial comments about Russian President Vladimir Putin.

"I have never been of this view that if you are a member of the royal family somehow you have to enter into some Trappist vow of silence," he told BBC Breakfast.

"I think he is entitled to his views. But I don't know whether those were his views because I just don't think providing a running commentary on what were private conversations is useful to anybody," Clegg said.

The Prince said, 'And now Putin is doing just about the same as Hitler'.

I must say that I agree with him and am sure a lot of people do.

But I was very surprised that he made the comment as I know they (members of the Royal Family) aren't meant to say these things.

I told the Prince that while my family and I were lucky to get a permit to travel, many members of my relatives had permits but were unable to get out before the war broke out on September 1. They were sent to the concentration camps and died.

After stepping off the plane, the Duchess, wearing a cream silk dress and golden black tweed coat, smiled as she was presented with flowers by Grace Elizabeth Lenihan, aged three, and her nine-year-old sister Molly Jane.

Camilla, who was carrying a black clutch bag given to her by a Canadian friend, told the young girls they looked "pretty" as she collected the gift.